Electric valve actuation can be used in internal combustion engine to provide increased flexibility in terms of valve timing and/or lift, rather than being constrained by camshaft actuation.
The inventors herein have recognized disadvantages with such systems in certain operating condition. Specifically, in some systems, the valve control that provides the desired valve timing is executed with some error during specific operating conditions. Likewise, in valve lift systems, the control that provides the desired lift can also be executed with some error during specific operating conditions. Also, this error can vary widely depending on the operating conditions. Furthermore, by the time this error is measured, or inferred, and used to correct the valve actuation, the cylinder event is already completed, or nearly completed. As such, it is generally available too late to be used to adjust valve timing for that cylinder event to reduce the error.
The above disadvantages are overcome by a system comprising:                an electrically actuated valve of an internal combustion engine;        a computer storage medium having instructions encoded therein for controlling said electrically actuated valve, said medium comprising:                    code for determining a desired valve condition for a cylinder cycle;            code for determining an actual valve condition occurring during said cylinder cycle;            code for determining an error between said desired valve condition and said actual valve condition for said cylinder cycle; and            code for adjusting a desired valve condition of a subsequent cylinder cycle based on said determined error.                        
By adjusting the valve operation of a subsequent cylinder cycle, it is possible to reduce potential errors in delivered valve timing or lift. In other words, in one example, the error can be learned for the condition under which it occurred, and then used the next time the engine operates at or near that condition so that the error can be reduced. In this way, improved accuracy can be achieved.
An advantage of the above aspect is that there is potential for improved air-fuel ratio control, torque control, emissions, etc.
Also note that the code can be in the form of machine instructions to carry out the corresponding code.